Now my Bua's(aunt) are claiming their share on this undivided property because both sons died before mom, hence mom becomes class 1 heir after the death of two sons..
Are they entitled ?
Are they entitled a share from the son's individual property as mom was alive at the time of their death and the ancestral property which is still undivided?
Someone said they are not entitled from undivided property as no partition has taken place.
First of all if the property, though ancestral, was in possession of your grandfather and he was termed as an absolute owner of those properties, then the very word 'ancestral' is extinguished.
It becomes your grandfather's own property and upon his intestate death it devolved equally on all his legal heirs or successors in interest i.e., children and wife, if the Hindu Succession law operates.
Thus all his legal heirs are entitled to 1/9th share in the property left behind by yor grandfather.
Your aunts being legal heirs of your grandfather are also entitled to 1/9th share equally at par with other shareholders.
Your grandmother being a legal heir again to her deceased sons, she is entitled to a share out of their individual shares in the property at par with their own and respective legal heirs as class I legal heir.
This is the position of law.
For further clarifications, you may produce the relevant documents and give more details of the property to the local lawyer who would be able to render more proper opinion after scrutinising the property related documents.